"Sometimes it's for people smuggling reasons; sometimes it's to simply get from one place to another to be able to work there."

Mr Williams estimates that on an Asian flight carrying 239 people, there are "probably" one or two people using stolen passports.

Mr Williams believes a combination of factors contribute to the lack of checks being performed at airports, including cost, the delay to passengers and "the fact that very rarely is it a problem that people are worrying about".

He says until now no-one has really paid attention to the use of stolen passports in international travel and he predicts that is likely to remain the case without a change in the system.

"There are a lot of people right now who are travelling on stolen passports and won't get picked up," he said.

"Unless there is a change in the system whereby all passports have to be checked against the Interpol database before travel occurs, it's not going to change."

Italian traveller tried to 'lock' passport after theft

Italian man Luigi Maraldi's passport was one of two confirmed stolen and used to board Malaysia Airlines flight MH370.

Mr Maraldi told a news conference his passport went missing last year after he used it as security to hire a motorbike in Phuket.

When he returned to the shop he was told his passport had been given to someone who looked like him.

Reporting the incident to both Thai and Italian police, Mr Maraldi says he was told by authorities in his homeland that the passport would be "locked" so it could not be used again.

"When I come back to Italy I talk with police, Italian police, [to] lock my passport so nobody can use [it]," he said.

Foreign Minister Julie Bishop says news of the stolen passports used to board the Malaysia Airlines flight is worrying.

"I note that a number of overseas authorities are involved in looking at this issue as to how many passengers were travelling on false or questionable passports," she said.

Australian passports are a hot commodity, with the Department of Foreign Affairs and Trade (DFAT) saying more than 30,000 are stolen or lost each year (see table).

DFAT says that 75 per cent of those passports are reported as having been lost or stolen within Australia.

"The next largest group of passports that are reported lost or stolen are done so in places which are popular tourist destinations for Australians, such as Paris, Madrid, Rome, London, Los Angeles and Bangkok," DFAT said in a statement.

Year

Lost or stolen passports

Number of travel documents on issue (millions)

2012-13

37,720

11.99

2011-12

38,062

11.52

2010-11

36,161

10.97

2009-10

36,099

10.41

2008-09

34,778

9.94

Source: The Department of Foreign Affairs and Trade

Australian ePassports, those which have been issued since October 2005, include a secure chip which includes a digital copy of the passport photo.

"The chip can be read at the border and the digital photo viewed and compared with the photo on the biodata page and the passport holder," the statement said.

"It is not possible to rewrite or alter an Australian ePassport chip. The Australian ePassport chip is locked. If someone attempts to alter the information the chip will shut down and become inoperable.

"Significant effort is put into the security features of the Australian ePassport to make it difficult to alter without alterations being evident."

DFAT documents show more than 2,300 Australian passports were reported stolen in Thailand over the previous decade to 2012.